Open a (free) Google Search Console [google.com] account.

This type of information is displayed the search analytics report, not by actual SERP page, but by where your site was in the order of results.

You can also get a lot of information with (free) Google Analytics [analytics.google.com]

Thank you, that's appreciated.

If you open these accounts, it may take some time for the reports to populate.

Thank you for the useful replies, it's appreciated.

Further to keyplyr's comment about the time it takes. I just launched two new sites over the past couple of months. In both cases it took well over a month before any usable data was available in GSC (Google Seach Console). Now if the site is already operational and getting traffic and you simply open an account, my guess would be that it will be faster to populate.

Analytics provides data immediately. But if you open a new account for an existing site it will only show data from the time the account was opened.

Thanks Nick. I have now opened a GA account, but really not understanding most of it. ;-(

You can do it through keywords position checker tool like SERP or small seo tools.

We can consider keywords position result through webmaster tool, it shows average position. To know the exact keyword position then we have to check through manually.